This rant about Mac OS X, multitasking and usability is brought to you by the letter Q and a disgruntled design student:
I heard something snap in my head today as I sat down at the back of an art history lecture hall (where outlets are, I follow) and got to peek over the shoulder of a girl using a 15" PowerBook in front of me.
This girl was using Safari to browse MySpace and - arguments about that site's damage to civilization as we know it aside - the browser window was 100% maximized across her 1280 x 960 display, obliterating what I would estimate is at least 1/3 of useful screen real estate. Then, she switched over to Word to keep working on a paper - again, Word had been manually maximized across the entirety of her widescreen display which was throwing easily half of her usable screen space into the garbage. Unfortunately, she is just one of many I have witnessed throwing away all sorts of useful screen space while using Mac OS X.
Men and women, boys and girls, please: Mac OS X more or less offers only one way to manually maximize windows across your entire display for a reason - because they don't have to be that large. "Multitasking" is defined as "the simultaneous execution of more than one program or task by a single computer processor." If we apply that definition to a person's ability to multitask, it means that you too are able to work on and look at more than one thing at once - which is why Mac OS X intentionally makes it difficult for one application to dominate the entirety of your display (Applications, such as Firefox, that don't obey the Mac OS X windowing rules I'm referring to are exempt from this post).
While the various tricks and design ideals that Mac OS X uses to accomplish this fantastic feat of productivity-inducing magic are outside the scope of my rant, I just want the word to get out that it is actually safe to trust your operating system's judgments in these kinds of matters. Tell your parents, inform you friends. I'm especially looking at you, switchers. I know the way Mac OS X handles windows and changing their size is strange, but trust me - once you get used to it and wrap your head around why it works this way on Apple's side of the fence, you'll be overjoyed with all the extra screen space you just reclaimed.
So go ahead, live on the edge: use that green "best fit" button and the Window > Zoom options, and be happy that you've taken a positive step towards getting just a little more done on your Mac.